JVI Figure table search 04
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zhang, M.
Right arrow Articles by Estes, M. K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhang, M.
Right arrow Articles by Estes, M. K.

 Previous Article  |  Next Article 

Journal of Virology, December 2000, p. 11663-11670, Vol. 74, No. 24
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

A Functional NSP4 Enterotoxin Peptide Secreted from Rotavirus-Infected Cells

Mingdong Zhang,1,dagger Carl Q.-Y. Zeng,1 Andrew P. Morris,2 and Mary K. Estes1,*

Division of Molecular Virology, Baylor College of Medicine,1 and Department of Pharmacology, Physiology, and Integrative Biology, University of Texas Health Science Center,2 Houston, Texas 77030

Received 27 March 2000/Accepted 3 October 2000

Previous studies have shown that the nonstructural glycoprotein NSP4 plays a role in rotavirus pathogenesis by functioning as an enterotoxin. One prediction of the mechanism of action of this enterotoxin was that it is secreted from virus-infected cells. In this study, the media of cultured (i) insect cells infected with a recombinant baculovirus expressing NSP4, (ii) monkey kidney (MA104) cells infected with the simian (SA11) or porcine attenuated (OSU-a) rotavirus, and (iii) human intestinal (HT29) cells infected with SA11 were examined to determine if NSP4 was detectable. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis-Western blotting, immunoprecipitation and N-terminal amino acid sequencing identified, in the early media from virus-infected cells, a secreted, cleavage product of NSP4 with an apparent molecular weight of 7,000 that represented amino acids 112 to 175 (NSP4 aa112-175). The secretion of NSP4 aa112-175 was not affected by treatment of cells with brefeldin A but was abolished by treatment with nocodazole and cytochalasin D, indicating that secretion of this protein occurs via a nonclassical, Golgi apparatus-independent mechanism that utilizes the microtubule and actin microfilament network. A partial gene fragment coding for NSP4 aa112-175 was cloned and expressed using the baculovirus-insect cell system. Purified NSP4 aa112-175 increased intracellular calcium mobilization in intestinal cells when added exogenously, and in insect cells when expressed endogenously, similarly to full-length NSP4. NSP4 aa112-175 caused diarrhea in neonatal mice, as did full-length NSP4. These results indicate that NSP4 aa112-175 is a functional NSP4 enterotoxin peptide secreted from rotavirus-infected cells.

* Corresponding author. Mailing address: Division of Molecular Virology, Mail Stop BCM-385, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030-3411. Phone: (713) 798-3585. Fax: (713) 798-3586. E-mail: mestes{at}bcm.tmc.edu.

dagger Present address: Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.

Journal of Virology, December 2000, p. 11663-11670, Vol. 74, No. 24
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Mol. Cell. Biol. Microbiol. Mol. Biol. Rev.
Clin. Vaccine Immunol. ALL ASM JOURNALS

Copyright © 2000 by the American Society for Microbiology. All rights reserved.